If you’ve ever learned about the koala bear in school or from reading a koala book, you’ll know that these furry critters love eucalyptus leaves. This isn’t the most nutritious of foods - in fact eucalyptus is poisonous to most animals and koalas have developed a specialised digestive system to break down the toxins in the leaves. 

But did you know that even though eucalyptus forms the bulk of a koala’s diet, they’re pretty fussy about which types of this tree they’ll eat? In fact, although there are over 600 types of eucalyptus trees in Australia, koalas refuse to eat most of them! So why are they so fussy about which leaves they munch on? Let’s find out. 

Different trees in different parts

Different parts of Australia have different species of eucalyptus tree - also called gum trees - growing there. This means a koala that lives in Victoria, for example, which is in the south of the continent, will have a different diet to one living on the coast of Queensland further north. 

Koalas in Victoria like River Red Gum, Forest Red Gum, Coast Manna Gum and Yellow Gum. Queensland koalas, meanwhile, enjoy a type of eucalyptus called Tallow Wood, as well as the Blue Gum, Swamp Mahogany, Spotted Gum and Small-fruited Grey Gum species. 

Nutrient levels

Because eucalyptus leaves are so low in nutrition, koalas must select the very juiciest and nutrient rich ones to feed on. These are often in the highest parts of the tree and koalas use their large noses to sniff them out. Research shows their superbly developed sense of smell means they can detect subtle differences in the chemical compounds of each leaf, choosing the tastiest and least toxic. 

Toxin levels

The Australian Koala Foundation notes that some eucalyptus leaves grow on less fertile soil and these seem to have a higher level of toxins than those growing on better quality soils. This could be one reason why koalas only eat certain types of eucalyptus - because even with their super strong digestive systems, they can’t process the most toxic leaves. 

Do koalas eat anything besides eucalyptus?

Eucalyptus makes up the vast majority of a koala’s diet, but they do feed on some related tree species such as brush box, paperbark and bloodwood. They have also been known to nibble on tea tree leaves occasionally. It all depends on where they’re living and the availability of their primary food source. 

Discover The Koala Who Could

If you’re a fan of the Rachel Bright and Jim Field picture books, don’t miss out on the stage adaptation of The Koala Who Could, which is currently touring the UK. Retelling the story with puppetry, songs and dancing, it’s a fantastic family show that’s perfect for children aged three and up. Discover what happens when Kevin the koala - who loves nothing more than clinging to his tree - is forced to venture down to the ground. Check out tour dates today and book your tickets at your local theatre.